Flexible transceivers for optical networks, along with suggested applications for their use, are described in K. Roberts and C. Laperle, “Flexible Transceivers”, Proc. ECOC, 2012. A flexible transceiver adapts to capacity availability and traffic demands by adjusting the transceiver configurations. A hitless flexible transceiver aims to adapt the transceiver configurations without interrupting network traffic.
S. L. Jansen, I. Morita, N. Takeda, H. Tanaka, “20-Gb/s OFDM Transmission over 4,160-km SSMF Enabled by RF-Pilot Tone Phase Noise Compensation”, in Optical Fiber Communication Conference and Exposition and The National Fiber Optic Engineers Conference, OSA Technical Digest Series (CD), (Optical Society of America, 2007), paper PDP15, which is incorporated herein by reference in its entirety, describes an RF-pilot aided phase noise compensation scheme in an orthogonal frequency division multiplexing (OFDM) system. An RF-pilot tone inserted at the transmitter gets the same phase distortions as the OFDM signal and is used to remove any phase distortions from the OFDM signal at the receiver.